ContaoCommunityAlliance/ComposerInstaller — pull request #3 by tristanlins (2013-02-21 20:21:59+00:00)
Title: Add partial installation support and contao metapackage

Now it is possible to define `target` OR `targets` in the `contao` section.
`target` define a module name in the `system/modules` directory.
`targets` is a map of paths to install in specific directories.

Example:
```javascript
{
"extra": {
"contao": {
"targets": {
"src/system/modules/nested-menu": "system/modules/nested-menu"
}
}
}
}
```

The contao metapackage is solved by naming the root package.
see https://github.com/ContaoCommunityAlliance/Composer/pull/2
The update hook look into the package and update the version if contao version changed.